The present invention relates to an injector for injecting coiled tubing into an oil or gas well.
Coiled tubing injectors are often used to inject coiled tubing into an oil or gas well to facilitate the servicing of the well. For some well-servicing applications, the diameter of the tubing must be increased in the upper sections of the tubing for reasons related to the well-servicing process.
One technique for accommodating an increase in diameter is to dispose a tapered connector between a relative small-diameter section and a relatively large diameter section. However, a problem arises in connection with this technique especially when the tubing passes through an injector for injecting it into the well. In particular, due to the rigidity of the injector structure, substantially all of the loading on the tubing provided by the injector is applied to the area of the connector having the relatively larger diameter. This results in a relatively small percentage of the exterior surface of the connector bearing substantially all of the loading, creating high stress areas at the points of contact with the injector, and possibly causing failure in the connector and/or the tubing.
Therefore, what is needed is an injector for passing coiled tubing through an injector that overcomes this problem.